Bumping gaia.json for 4 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/c4a9b3d6aeac
Author: Anthony Ricaud <anthony@ricaud.me>
Desc: Merge pull request #23481 from etiennesegonzac/bug-1039455-follow-upt

Bug 1039455 follow up - Updating the l10n key in the test file too. r=alive

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https://hg.mozilla.org/integration/gaia-central/rev/ef0704cc7a2a
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Bug 1039455 follow up - Updating the l10n key in the test file too.

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https://hg.mozilla.org/integration/gaia-central/rev/cf093c66a981
Author: Anthony Ricaud <anthony@ricaud.me>
Desc: Merge pull request #23482 from alivedise/bugzilla/1060344/gij

Bug 1060344 - Fix layout manager ref error r=etienne

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https://hg.mozilla.org/integration/gaia-central/rev/813389e5a551
Author: Alive Kuo <alegnadise@gmail.com>
Desc: Bug 1060344 - Fix layout manager ref error
Bumping manifests a=b2g-bump